疏水型纤维素基絮凝材料的制备及其溶剂体系回用的研究

发布时间：2017-12-31 00:33

本文关键词：疏水型纤维素基絮凝材料的制备及其溶剂体系回用的研究　出处：《浙江理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着工业的发展,工业废水的排放量也随之增大,其中就有高浓度的氨氮废水。在预处理去除废水中的悬浮颗粒和染料的过程中,絮凝是最方便有效的方法,在絮凝的过程中会产生大量的污泥。目前絮凝剂主要有有机合成絮凝剂和天然高分子絮凝剂,有机合成絮凝剂有优异的絮凝性能,但是存在难降解、原料不可再生等缺点,因此,越多越多的学者把目标放在无毒、可再生、可降解的天然高分子上。用絮凝剂处理会产生大量的含水量高的污泥,这会增加污泥的后期运输和处理的成本,对絮凝剂进行疏水改性具有重要的现实意义。本研究采用竹浆纤维素作为基体材料,采用一步法制备不同zeta电位的纤维素基絮凝剂。其合成过程为用氢氧化钠和尿素溶解纤维素(纤维素的浓度为2%)后,过硫酸铵在55℃时引发,加入丙烯酰胺反应3小时。丙烯酰胺在氢氧化钠的作用下会发生水解,通过加入丙烯酰胺量的不同,最终得到五种不同zeta电位的纤维素基絮凝剂产品。通过红外光谱、氢谱和扫描电镜来验证纤维素结构和性能的变化,将此絮凝剂用于处理高岭土模拟废水,通过实验发现具有较为优异的絮凝性能,部分产品的效果优于商业CPAM和PAC,最后应用于造纸废水的处理,也表现出较好的絮凝性能。将上述合成的产品进行疏水改性,通过控制硅酸钠和纤维素中葡糖糖单元的质量比,来合成不同疏水性能的疏水型纤维素基絮凝剂,在55℃下,加入不同量的硅酸钠反应4小时,然后再熟化8小时,即得到了疏水性不同的疏水型纤维素基絮凝剂。随着硅酸钠含量的增加,污泥比阻和污泥沉降比也随之下降,说明疏水性能逐渐变好,zeta电位逐渐升高,这有助于絮凝的电中和作用,最后用于处理不同的工业废水,都表现出较为出色的絮凝性能。由于合成的过程是在氢氧化钠尿素体系中,将废液直接倒入环境中会增加水中的氨氮含量,因此要对其进行循环回用。首先用凯氏定氮法和中和滴定法分别测定溶液中的尿素和氢氧化钠的含量,然后在加入一定量的固体,配成新的纤维素溶解液对纤维素基絮凝剂进行再合成。通过红外光谱观察其分子结构的变化,通过絮凝高岭土和工业废水观察其絮凝性能,实验表明,经循环使用的纤维素溶解液合成的纤维素基絮凝剂与原纤维素溶解液制备的纤维素基絮凝剂都具有优异的絮凝性能。
[Abstract]:With the development of industry, industrial wastewater emissions also increased, which has high concentration of ammonia nitrogen wastewater. In the process of pretreatment of wastewater containing suspended particles and dyes, flocculation is the most convenient and effective method, in the flocculation process will produce large amounts of sludge. The flocculant is mainly organic synthesis flocculant, natural polymer flocculant, organic synthesis flocculant had excellent flocculation performance, but are difficult to degrade, non renewable raw materials and other shortcomings, therefore, more and more scholars focus on renewable, non-toxic, biodegradable natural polymer. With high water containing sludge produced by flocculant, which will increase the late sludge transportation and disposal costs, has important practical significance to the hydrophobic modification of flocculant. This study uses bamboo cellulose as matrix material, preparation of different Ze by one-step process Cellulose based flocculant TA potential. The synthesis process with sodium hydroxide and urea dissolved cellulose (cellulose concentration 2%), had caused ammonium sulfate at 55 DEG C, adding acrylamide reacted for 3 hours. Acrylamide hydrolysis occurs under the action of sodium hydroxide, by adding different amount of acrylamide, to obtain cellulose based flocculant products five different Zeta potential. By infrared spectroscopy, spectroscopy and scanning electron microscopy to verify the change of the structure and properties of cellulose, the flocculant for kaolin wastewater treatment, flocculation experiments found that has more outstanding performance, the product is better than the commercial CPAM and PAC processing, finally used in papermaking wastewater. It shows better flocculation property. The synthesized products were hydrophobically modified, the quality control of sodium silicate and cellulose glucose unit than to. The hydrophobic cellulose based flocculant synthesis with different hydrophobic properties, under the temperature of 55 DEG C, adding sodium silicate reaction of different amounts of 4 hours, and then cooked for 8 hours, which is the hydrophobic cellulose based flocculant of different hydrophobicity. With the increase of the content of sodium silicate, specific resistance of sludge and sludge settling ratio also decreased. That hydrophobic performance becomes better, the zeta potential gradually increased, which contributes to the flocculation of charge neutralization, finally used for industrial wastewater treatment are different, showing more excellent flocculation performance. Because the synthesis process in sodium hydroxide urea system, waste directly into the environment will increase the ammonia nitrogen content in water, so to carry on the recycle. First by Kjeldahl content in solution of sodium hydroxide and urea nitrogen determination method and neutralization titration respectively, then adding a certain amount of solid, with new cellulose solution The solution of cellulose based flocculant was synthesized. The change of the molecular structure observed by infrared spectroscopy, observe its flocculation performance, kaolin and industrial wastewater by flocculation experiment showed that the recycled cellulose based flocculant dissolution of cellulose liquid synthesis of cellulose based flocculant and cellulose dissolving has excellent flocculation performance.

【学位授予单位】：浙江理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB34

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